An analysis of 483 remotely operated vehicle (ROV) dives carried out along the Italian coast on hard substrata at mesophotic depths (40–200 m) allowed an overview of the rich sponge diversity (53 taxa) of the deep continental platform to be obtained for the first time. About 40% of the potential actual species diversity was recognisable using ROV, suggesting that this group is among the richest yet underestimated using this te...

This study provides new insights onto spatial and temporal trends of seafloor macro-litter in the abyssal seafloor of Sardinian channel, in central western Mediterranean (Italy). Trawl surveys were conducted at depths between 884 and 1528 m, thus focusing on one of the least investigated marine environments. None of the considered sites was litter free, with plastics being numerically dominant (57% of items), followed by metal...

Due to their late maturation, extreme longevity, low fecundity and slow growth rates, deep-sea Chondrichthyes are extremely vulnerable to human impacts. Moreover, assessing the impact of deep-sea fisheries is difficult, as many species (including sharks) are part of the bycatch and are often discarded at sea, and/or landed under generic commercial-species codes. The lack of this information on fishery data sets and the limited...

The present study, based on microsatellite markers, describes a population genetic analysis of the small-spotted catshark Scyliorhinus canicula (Linnaeus, 1758), representing one of the most abundant and commonly caught cartilaginous fishes in the Mediterranean Sea and adjacent areas. The analyses were performed to unravel the genetic features (variability, connectivity, sex-biased dispersal) of their relative geographic popul...

Bivalve mollusk production represents the principal aquaculture activity in Sardinia (40°03′ N, 9°05′ E). In 2021, 859 water samples and 1270 mollusk samples were analyzed. The species Alexandrium minutum caused the accumulation of Paralytic Shellfish Toxins (PST) in three samples of bivalve mollusks. Dinophysis acuminata complex caused the accumulation of lipophilic toxins (LTs) belonging to the okadaic acid group (OAs) in 18...

The precious coral Corallium rubrum (Linnaeus, 1758) is a charismatic Mediterranean species. A recent large-scale investigation along the Italian coast highlighted its widespread occurrence at mesophotic and upper bathyal depths, especially on coralligenous and bathyal vertical hardgrounds. The lack of morphometric data limited the considerations on the structure and health status of the populations, fundamental to identify th...

The presence of plastic waste in the marine environment has driven the scientific community to make significant efforts to study and mitigate its possible effects. One of the critical aspects is to determine if and how an increase in ingestion events may occur as a result of the accumulation of plastic waste on the seabed. In this study, G. melastomus is examined for its ability to indirectly provide information on the amount...

The analysis of 879 ROV dives carried out along the Italian coasts on hard substrata at mesophotic and upper bathyal depths (40-775 m) allowed us to evaluate the current basin-scale presence, relative abundance, bathymetric limits, and habitat preferences of one of the most charismatic Mediterranean habitat-former anthozoan species, Corallium rubrum (Linnaeus, 1758). The species is widespread, and its occurrence ranged from 13...

Plastic waste dumped in the marine environment has severe ecological, social and economic impacts. In recent years, a series of scientific studies documented the contamination by macroplastic and its impact on marine organisms through the accidental ingestion of microplastics, which also originate from the degradation of macroplastic. However, the relationship between the spatial distribution of marine litter and the ingestion...

Molecular identifications based on two mitochondrial markers (cytochrome c oxidase subunit I -COI- and 16S ribosomal RNA gene -16S-) have been implemented to confirm the morphological identification of eight specimens collected in the Central western Mediterranean. Molecular data show they belonged to a recently resurrected species of the genus Ommastrephes , i.e., O. caroli , known to be distributed in the Atlantic Ocean and...

Annual and interannual dynamics of shellfish toxins and associated harmful algal species (HAS) were analyzed from 2015 to 2020 in Tortolì Lagoon (Sardinia, west Mediterranean Sea). Analysis of seasonal occurrence of different harmful algae, such as Dinophysis spp., Prorocentrum spp., Pseudo-nitzschia spp. and Alexandrium minutum, was performed. The species Dinophysis acuminata and Dinophysis sacculus were responsible for the a...

The white skate Rostroraja alba is assessed by the International Union for Conservation of Nature as Endangered globally and is now considered rare in the Mediterranean. This species has never been recorded in Sardinian seas (central western Mediterranean), but an empty eggcase was collected on a sandy bottom off the western Sardinia coasts during the MEDiterranean International Trawl Survey (MEDITS) program in 2019. A morphom...

As far as is known, in this paper the first case of lacking of skin‐related structures (epidermis, stratum laxum , dermal denticles and teeth) in a free‐swimming elasmobranch, the blackmouth catshark, Galeus melastomus , is reported. The individual was caught by trawl in Sardinian waters (central‐western Mediterranean) in July 2019 at a depth of 500 m. Although this kind of morphological abnormality is potentially fatal, the o...